Synthesis of NaA Zeolite: Conventional Route and Green Route

Abstract

The research describes a sustainable approach for the synthesis of zeolite NaA using kaolin as an alternative source of silica. The main objective of this research was to prepare NaA zeolite using metakaolin derived from kaolin from the state of Rio Grande do Norte, Brazil, as an alternative source of silica, reducing the production cost and evaluating its thermal stability. In addition, a study of the thermal stability of the zeolite and cost estimates for zeolite production were carried out. Traditional methods of zeolite synthesis, mainly through hydrothermal processes, are often associated with high costs, waste generation, and negative environmental impacts. This work addresses these concerns by exploring a more sustainable approach. The kaolin used in the study was characterized by X-ray diffraction, energy-dispersive X-ray fluorescence spectroscopy, infrared spectroscopy, and thermogravimetry. These techniques help confirm the composition and properties of the raw material. NaA zeolite was synthesized by replacing sodium silicate with metakaolin using the hydrothermal synthesis method. The NaA zeolite was characterized by XRD and IR, which helped verify its purity and structural order. The study's results demonstrated that kaolin waste mainly consists of kaolinite, which suggests that it can be effectively used as a source of silica. Furthermore, the research successfully produced low-cost NaA zeolite in a relatively short synthesis time, achieving high purity and structural order. The study highlights the potential of using kaolin waste as a sustainable source of silica for zeolite production, helping to minimize environmental impacts and reduce processing costs compared to traditional methods. This work presents a promising and sustainable method for producing NaA zeolite from kaolin waste, which has the potential to contribute to cost reduction, waste reduction, and improved environmental sustainability in zeolite production processes. This research is aligned with the broader goals of reducing the ecological footprint of industrial processes while maintaining product quality and efficiency.